Language Configuration

In normal cases, ownCloud will automatically detect the language of the
Web-GUI. If this does not work as expected, or you want to make sure that
ownCloud always starts with a given language, you can use the
default_language configuration parameter.

This parameter can be set in config/config.php

Parameters

'default_language' => 'en',

Please keep in mind, that this will not effect a users language preference,
which can be configured under SettingsPersonalGeneralLanguage once he has logged in.

More supported languages can be found in directory <ownCloud_root>/settings/l10n. List all files with ls *.js.
The language code to be used is the filename without extension.